Comparing effects of educational interventions on literacy skills in Grade 1

Two large-scale studies examined  the effects of policy and educational interventions on literacy skills in children schooled in zones with specific educational needs. To calculate the potential effects of such interventions, treatment-effects estimators with nearest neighbor matching were used. In Study 1 with policy intervention (N = 1095), children in experimental group (Exp) were assigned to small classes (12 pupils) and others in control group (Cont) to normal-sized classes (20–25 pupils). At the end of Grade 1, the effect sizes in favor of Exp were .14 and .22 in word reading and spelling. In Study 2 with educational interventions (N = 2803), children in Exp benefit from an evidence-based practice, i.e. a code-focused intervention (phonology, letter knowledge, decoding and fluency) conducted by teachers in small groups for children with low performance at the beginning of Grade 1. The effect sizes of interventions in various literacy skills were from .12 to .32. This set of results is in accordance with those described in other countries. To conclude, a double intervention with small classes and targeted educational approaches could be one of the best ways of reducing inequalities during learning to read.